People who carry a certain genetic variation are much more likely to develop the most dangerous form of skin cancer, Portuguese researchers said recently.

Their study, presented at the Congress of the European Society for Medical Oncology in Stockholm, showed the variation in a gene known as cyclin D1 raised the risk of developing the cancer by 80% compared to those without the mutation.

Cyclin D1 is part of the mechanism that speeds up or slows down cell growth. Previous research has linked changes in the way it functions to several tumors, including skin and breast cancer.

"Our results indicated that the proportion of melanoma cases attributable to this genetic alteration is 14%," Raquel Catarino of the Portuguese Institute of Oncology in Porto, said in a statement.

Melanoma, caused by exposure to the ultraviolet light in sunlight, is an aggressive, difficult-to-treat cancer with an average survival rate of about six months for people with advanced stages of the disease. The World Health Organization estimates that as many as 60,000 people each year die from excessive exposure to ultraviolet light, mostly from malignant melanoma.

Catarino and colleagues analyzed the blood of 1,053 volunteers, including 161 people with melanoma and 892 healthy men and women. They found that people carrying two copies of the variant were 80% more likely to develop melanoma.

"Once the genetic factors involved in melanoma...are identified and their importance established and validated, the individual's genetic profile could help clinical decisions," Catarino said.